The invention relates to a panel system with variable transparency, in which two essentially transparent panels are connected by a resilient seal which permits the distance between the panels to be varied by controlling the thickness of a liquid layer between the panels, and more particularly, relates to the use of such a panel system in a sliding/lifting roof cover of a vehicle.
Such a panel system with two transparent panels, disposed essentially parallel to each other, with a resilient seal connecting both panels in a manner which permits a change in the amount of light ray absorbing liquid located between the two panels via a control element admitting and withdrawing liquid to and from a liquid reservoir and a cavity between the panels is known, for fixed windows of buildings and motor vehicle windshields, from British Patent 1,145,060. The liquid reservoir and the transport element described therein are arranged externally of the panel system at a location spaced therefrom. Such an arrangement as is described therein can be utilized for windows of buildings without significant drawbacks. However, for usage in a movable cover of a vehicle sliding/lifting roof, such a panel system is hardly suitable. That is, for the cover to be moved for the purpose of exposing a roof opening, leading to and from the reservoir, the hose lines would have to be carried along, which, in turn, would result in an unsightly appearance and premature wear of the hoses.